Telephone-receiver.



W. H. COTTON.

TELEPHONE RECEIVER.

APPLICATION FILED OOT.25, 1912.

1 .1 15,053. Patented 0012.27, 1914.

6'6 Iva/1 of the receiver and 15 designates, as a WALTER H. COTTON, OF CHICAGO, ILLINOIS.

TELEPHONE-RECEIVER.

Specification of Letters Patent.

Patented Oct. at, 1914-.

Application filed October 25, 1912. Serial No. 727,673.

To a whom it may com-cm :0 it known that I, \VALrnn I-I. Co'rrox, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Telephone-Re ceivers; nd I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and t0 the eha meters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in telephone receivers and refers more specifically to means for clarifying the tones reproduced at the diaphragm so as to avoid the shocks and annoyances to the human ear due to excessive vibrations of the diaphragm and also to annoyances due to the less dis tiiutvibrations of the radially outer portion of the diaphragm which tend to confuse the effects of the more distinct vibrations of the central portion of the diaph 'agm.

To attain the first object of the invention it is one of the purposes thereof-to limit the vib 'ation of the central portion of the diaphragm beyond a certain amplitude and thereby dissipate the annoying cracking sounds thrown upon the ear drum due to excessive vibration.

To attain the second object of the inven tion it is the purpose thereof to shut out or trap the less distinct vibrations which emanate from the diaphragm radially extericr to the more effective central portion thereof and which less distinct vibrations, in a receiver of ordinary construction, tend to confuse the general sound reproducing effect of the diaphragm.

In the drawings: Figure 1 is a side elevation, partly in section, of a receiver embodying my invention, the section portion thereof being taken on the line 11 of Fi 2. Fig. 2 in a front and view of the coup ing sleeve constituting part of the ear piece of my improved receiver. Fig. 3 is a similar view of a modified form of the coupling sleeve. Fig. 4 isa section on the line 4--4 of Fig. 3.

As shown in the drawings, 10 designates the body of the receiver having the usual binding post connection at the rear end for the wires 11, 11 of the listening circuit.

14 designatest-he usual diaphragm which extends across the enlarged ear piece end whole,

the usual combined permanentand electromagnets in rear of the diaphragm. The said disk 1* is confined at its margins between the end margins of the enlarged portion 16 of the body and an internal shoulder formed on a coupling sleeve that embraces a part 17 which is interiorly scrcw-tln'eaded to engage an exterior screw-thread on said cnlargcd portion 16. and a portion 18 of reduced diameter that is extcriorly screwthr aded to engage the interior screw-thread of a detachable car piece 19. The said coupling sleeve, therefore, constitutes a connection between the body of the receiver and the ear piece. The coupling sleeve constitutes means whereby a standard receiver body may be attached to a standard ear piece, and to clamp the diaphragm in place. The ear piece may be specially formed to engage the body and to clamp the diaphragm in place. The ear piece is provided with the usual central opening 20 at the base of the usual recess 21 formed in the face thereof.

The said coupling sleeve comprises also a disk or late 22 which extends across the opening 0 the receiver body and arranged at a right angle to said body. The said disk or plate lar member 24 which fits at its outer end within the central opening of the ear piece. This tubular portion may be formed integral with the plate 22, as shown in Figs. 3 and 4, wherein it is shown as connected to the plate or disk by the spider arms 25 and arranged to provide between the tubular member and plate an opening or openings 26 to afford communication between the in ner and the outer sides of said plate 22. Alternately, said tubular member and its arms may be formed integral with an exteriorly screw-threaded ring 28 that is fitted into and engages an interior screw-thread of an opening of the plate or disk 22 concentric with the axis of the ear piece opening 20. In this construction the ring 28 is formed between the spider arms 25 thereof with openings to afford communication from the inner to the outer side of said plate 22.

The diaphragm is shown as bowed or dished inwardly at its center toward but not in contact with the pole or poles of the permanent magnet, as is common in the type of receiver shown; the normal inward bowing of the diaphragm being due to the attraction of the pole or poles of the permanent magnet.

22 carries at its center a tubu- In accordance with one feature or my invention the margin of the diaphragm may be clamped directly between the end of the body 10 and the disk or plate and said plate is provided at its central portion and on its inner side around the axis of the tubular member with a thickened or raised portion 30 which is arranged in a plane inside the plane of the margin of the diaphragm and inside the plane assumed by the diaphragm when not under the influence of the permanent magnet. The inner end of the tubular member is preferably arranged in the plane of the inner face of said thickened or raised portion. As shown in Figs. 1 and the said raised portion 30 is formed by the inner end of the ring 28, while in Fig. at it is formed by an integral portion at the plate The efi'ect of the magnet is to hold the diaphragm suspended, so to speak, between the abutment 30 and the poles of the magnet. and said magnet poles and abutment limit the amplitude of vibration of the diaphragm.

13y reason of the disposal of the raised portion of the plate or disk 22 in a plane inside the plane of the confined margin of the diaphragm. and, therefore, inside a plane which would be otherwise occupied by the flattening ot' the diaphragm, if not under the influence of the magnet 15, excessive amplitude ot vibration of the diaphragm is prevented and, therefore, annoying loud clicking noises in the receiver are averted when the inductance in the electro-magnet is high. The central part of the diaphragm is normally maintained suspended between the poles of the magnet and the abutment 30,

and in the normal use of the receiver the amplitude of vibration between the opposing parts is sufiicient to produce clear reproduction of sound. In case of high inductance on the listening circuit, for any reason, and a tendency toward a greater than normal amplitude of vibration in the diaphragm, such vibration is arrested by the central abutment 80 so that excessive vibra' tions are thereby dampened or dissipated with the result of avoiding sharp and annoying cracking sounds in the receiver, thereby producing clear and clean out sound reproductions.

By reason of the provision of the tubular mem er 24 which extends from near the central part of the diaphragm to the opening in the ear piece, and the opening or openings 36 radially exterior to said tubular memher. the sound reproducing effect of the central portion of the diaphragm, or that which transmits the clearest and most pronounced sound waves, is transmitted through the listening zone of the transmitter, circumscribed by said tubular member 24; while the more feeble vib ations of the diaphragm,

radially exterior to the said tubular member, are trapped within the space 85 between the plate 22 and the ear piece 19, and are not transmitted to and do not efi ect the clarity of the reproduced sound transmitted to the human ear. These side sounds may escape through the openings 26 into the space 35 and be there absorbed, or may be dissipated therefrom in any suitable manner.

I have found, in practice, that the device described greatly clarifies the sound produced from the vibrations of the diaphragm, both by reason of the dampening of the vibrations of excessive amplitude of the diaphragm, and by reason of the trapping of the feeblervibrations from the portions of the diaphragm exterior to the tubular member 24. Moreover, all the effective sound waves which are reproduced as sound on the human ear pass directly to the ear drum, thus avoiding confusion due to the indirect passage of a portion of the sound waves from the diaphragm ot' the ordinary receiver.

It will be understood that the structural details of the device may be varied within the spirit and scope of the invention, and the invention is therefore, not limited to the structural details shown, except. as hereinafter made the subject of specific claims and as imposed by the prior art.

I claim as my invention 1. In a telephone receiver and the like, the combination with a vibratory magnetic diaphragm having means to confine it at its margin, of a combined permanent and electro-magnetand a fixed abutment disposed respectively on the opposite sides and centrally of said diaphragm with the pole of the permanent magnet opposing the center of the said diaphragm, said diaphragm being held in suspension by the action of the magnet between and out of contact with said abutment and the pole of said magnet and bowed toward said pole, and said abutment being disposed in a plane within that of the confined margin of the diaphragm.

A telephone receiver comprising, in combination with a body and a magnet therein, a magnetic diaphragm across the open end of the body in the influence of and centrally bowed toward but normally out of contact with the pole of said magnet, and a plate between which and the body the margin of the diaphragm is confined, said plate being provided with a central opening and on its inner side around said opening with a non-yielding raised portion disposed in a plane within the plane of the margin of said diaphragm, and normally out of contact with said diaphragm.

3. A telephone receiver comprising, in combination with a body and a magnet therein, a magnetic diaphragm across the open end of the body in the influence of I the combination with a permanently confined vibratory magnetic diaphragm, of a combined permanent and electro-magnet and a fixed abutment disposed respectively on the opposite sides and centrally of said diaphragm, said diaphragm being held in suspension by the action of the permanent magnet between and out of contact with said abutment and the pole of said magnet and normally bowed toward said pole, with the abutment disposed in a plane within that of the periphery of the diaphragm, said receiver being provided exterior-to the diaphragm with a free passage for sound waves which emanate from the central portion of the diaphragm and means for trapping the vibrations which emanate from the diaphragm radially exterior to said passageway.

5. In a telephone receiver and the like, the combination with the vibratory magnetic diaphragm, of a permanent magnet and a fixed abutment disposed respectively on the opposite-sides of the said diaphragm, with the pole of the said magnet presented centrally to said diaphragm whereby the diaphragm is centrally bowed toward the magnet but normally out of contact with the magnet and the abutment, there being a circumscribed free passageway leading from the central part of the diaphragm to a corn tral aperture of the ear piece, and means for directing sound waves which emanate from the diaphragm radially exterior to said passage to a point outside of the listening zone of the ear piece.

6. A telephone receiver provided with a diaphragm and with a centrally apertured ear piece, a disk or plate lying over the outer face of the diaphragm and provided with a central opening and with a tubular member which extends from saidopening to said central aperture of the ear piece, said disk and tubular member being centrally out of contact with the diaphragm, and provided exterior to said tubular member with openings in communication with a chamber between the diaphragm and the ear piece and surrounding the said tubular member.

7. A receiver comprising a body having an exterior screw-thread and ear piece pro vided with an interior screw-thread, an oil'- set coupling piece screw-threaded to the ear piece and connecting said body and ear piece, a diaphragm extending across the open end of the receiver body and clamped at its margin between the body and the offset coupling piece, a magnet presented centrally to but normally out of contact with said diaphragm to cause the diaphragm to normally bow toward the magnet, and means between the diaphragm and ear piece and normally out of contact with the diaphragm and in a plane within that of the diaphragm margin to isolate the sound waves emanating from the central part of the diaphragm to transmit them through the ear piece, and for trapping the vibrations emanating from the remaining parts of the diaphragm.

8. A receiver comprising a body having an exterior screw-thread and ear piece provided with an interior screw-thread, an oliset coupling piece screw-threaded to and connecting said body and ear piece, a diaphragm extending across the open end of the receiver body, and clamped at its margin between the body and the offset coupling piece, a disk extendin across the diaphragm exterior thereto and provided centra ly thereof with a tube which extends to the central opening of the ear piece and is out of contact with said diaphragm, and means whereby the yibration emanating from the diaphragm exterior to said tube are trapped in the annular space between the diaphragm and the ear piece surrounding the tube.

In testimony, that I claim the foregoing as my invention I affix my signature in the presence of two witnesses, this 22nd day of October, A. D. 1912.

WALTER H. COTTON.

Witnesses G. E. Downs, W. L. HALL.

Copies of this patent may be obtained for five cents each, by addressing the "Commissioner of latentn,

Waehington, D. 0." 

